Transcranial direct current stimulation as treatment for Parkinson’s disease and other movement disorders

Movement disorders have been traditionally regarded as disorders affecting motor control that result from dysfunction in basal ganglia circuitry. Currently, treatment options are symptomatic medications or surgical intervention (i.e., deep brain stimulation). Motor rehabilitation represents another important treatment option for reducing motor dysfunction and improving quality of life. Several studies have highlighted the therapeutic potential of transcranial direct current stimulation (tDCS) in patients with neurological diseases, including dementia, epilepsy, post-stroke dysfunctions, movement disorders, and other pathological conditions. This brief review focuses on available data regarding the effects of tDCS on motor ability and cognition in people with movement disorders. Findings indicate that tDCS is a promising therapeutic tool especially for Parkinson's disease. However, its efficacy in treating other movement disorders appears limited given the current data. Future research efforts should be directed at identifying optimal stimulation parameters (e.g., site, electrode montage and size, duration, intensity, number of sessions, on-line vs. off-line, duration of treatment) for specific types of movement disorders and even for customization for individual patients.